This invention relates to a method and apparatus for threshing the mid-ribs from tobacco leaves and the like.
In the prior art, as disclosed in Japanese Patent Publication No. 50-6558, for threshing the mid-ribs from tobacco leaves by means of a threshing gear and a basket which are rotated independently within a spiral casing, raw material is supplied from a spiral supply port axially adjacent to said both threshing gear and basket by means of a circulating air flow and through a spiral fan. It is almost impossible for this type of apparatus to supply a large quantity of raw material or treat a large quantity thereof at a time.